Delivery Systems and Methods of Implantation for Prosthetic Heart Valves

ABSTRACT

A method of deploying an implantable stented device in an anatomical location of a patient, including the steps of providing a delivery system with first and second stent engagement structures at its distal end, attaching a first structural element of the stented device to the first stent engagement structure and attaching a second structural element of the stented device to the second stent engagement structure, advancing the stented device to an implantation site, and sequentially disengaging the first structural element of the stented device from the first stent engagement structure of the delivery system and then disengaging the second structural element of the stented device from the second stent engagement structure.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional ApplicationNo. 61/062,207, filed Jan. 24, 2008, and titled “Delivery Systems andMethods of Implantation for Prosthetic Heart Valves”, the entirecontents of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to prosthetic heart valves. Moreparticularly, it relates to devices, methods, and delivery systems forpercutaneously implanting prosthetic heart valves.

BACKGROUND

Diseased or otherwise deficient heart valves can be repaired or replacedusing a variety of different types of heart valve surgeries. Typicalheart valve surgeries involve an open-heart surgical procedure that isconducted under general anesthesia, during which the heart is stoppedwhile blood flow is controlled by a heart-lung bypass machine. This typeof valve surgery is highly invasive and exposes the patient to a numberof potentially serious risks, such as infection, stroke, renal failure,and adverse effects associated with use of the heart-lung machine, forexample.

Recently, there has been increasing interest in minimally invasive andpercutaneous replacement of cardiac valves. Such surgical techniquesinvolve making a very small opening in the skill of the patient intowhich a valve assembly is inserted in the body and delivered to theheart via a delivery device similar to a catheter. This technique isoften preferable to more invasive forms of surgery, such as theopen-heart surgical procedure described above. In the context ofpulmonary valve replacement, U.S. Patent Application Publication Nos.2003/0199971 A1 and 2003/0199963 A1, both filed by Tower, et al.,describe a valved segment of bovine jugular vein, mounted within anexpandable stent, for use as a replacement pulmonary valve. Thereplacement valve is mounted on a balloon catheter and deliveredpercutaneously via the vascular system to the location of the failedpulmonary valve and expanded by the balloon to compress the valveleaflets against the right ventricular outflow tract, anchoring andsealing the replacement valve. As described in the articles:“Percutaneous Insertion of the Pulmonary Valve”, Bonhoeffer, et al.,Journal of the American College of Cardiology 2002; 39: 1664-1669 and“Transcatheter Replacement of a Bovine Valve in Pulmonary Position”,Bonhoeffer, et al., Circulation 2000; 102: 813-816, the replacementpulmonary valve may be implanted to replace native pulmonary valves orprosthetic pulmonary valves located in valved conduits.

Various types and configurations of prosthetic heart valves are used inpercutaneous valve procedures to replace diseased natural human heartvalves. The actual shape and configuration of any particular prostheticheart valve is dependent to some extent upon the valve being replaced(i.e., mitral valve, tricuspid valve, aortic valve, or pulmonary valve).In general, the prosthetic heart valve designs attempt to replicate thefunction of the valve being replaced and thus will include valveleaflet-like structures used with either bioprostheses or mechanicalheart valve prostheses. In other words, the replacement valves mayinclude a valved vein segment that is mounted in some manner within anexpandable stent to make a stented valve. In order to prepare such avalve for percutaneous implantation, the stented valve can be initiallyprovided in an expanded or uncrimped condition, then crimped orcompressed around the balloon portion of a catheter until it is as closeto the diameter of the catheter as possible.

Other percutaneously delivered prosthetic heart valves have beensuggested having a generally similar configuration, such as byBonhoeffer, P. et al., “Transcatheter Implantation of a Bovine Valve inPulmonary Position.” Circulation, 2002; 102:813-816, and by Cribier, A.et al. “Percutaneous Transcatheter Implantation of an Aortic ValveProsthesis for Calcific Aortic Stenosis.” Circulation, 2002;106:3006-3008, the disclosures of which are incorporated herein byreference. These techniques rely at least partially upon a frictionaltype of engagement between the expanded support structure and the nativetissue to maintain a position of the delivered prosthesis, although thestents can also become at least partially embedded in the surroundingtissue in response to the radial force provided by the stent andballoons that are sometimes used to expand the stent. Thus, with thesetranscatheter techniques, conventional sewing of the prosthetic heartvalve to the patient's native tissue is not necessary. Similarly, in anarticle by Bonhoeffer, P. et al. titled “Percutaneous Insertion of thePulmonary Valve.” J Am Coll Cardiol, 2002; 39:1664-1669, the disclosureof which is incorporated herein by reference, percutaneous delivery of abiological valve is described. The valve is sutured to an expandablestent within a previously implanted valved or non-valved conduit, or apreviously implanted valve. Again, radial expansion of the secondaryvalve stent is used for placing and maintaining the replacement valve.

Some delivery systems used for percutaneous delivery of heart valveshave had associated issues with the heart valves sticking or otherwisenot consistently releasing from the delivery system for deployment intothe desired location in the patient. In these cases, the delivery systemcan be further manipulated, which may cause the valve to becomedislodged from the desired implantation location or cause other traumato the patient. In rare cases, the heart valve cannot be released fromthe delivery system, which can then require emergency surgery tointervene. Such surgery can expose the patient to significant risk andtrauma.

Although there have been advances in percutaneous valve replacementtechniques and devices, there is a continued desire to provide differentdesigns of cardiac valves that can be implanted in a minimally invasiveand percutaneous manner. There is also a continued desire to be able toreposition and/or retract the valves once they have been deployed orpartially deployed in order to ensure optimal placement of the valveswithin the patient. In particular, it would be advantageous to provide avalve and corresponding delivery system that allow for full or partialrepositionability and/or retractability of the valve once it ispositioned in the patient. In addition, it would be advantageous toprovide a delivery system that can consistently release a heart valvewithout inducing the application of force to the stented valve that candislodge the valve from the desired implantation location. Finally, thecomplexity and widely varying geometries associated with transcathetervalved stents and the complex anatomies that they are designed toaccommodate present a need to be able to sequentially release specificregions or portions of the transcatheter valved stent. This enablesspecific advantages to position the devices more accurately and/ordeploy specific features for anchoring, sealing, or docking of thedevices. Additionally, the ability to sequence the release of variousregions of different radial force and/or geometry is important inimproving deliverability of transcatheter valve devices.

SUMMARY

Replacement heart valves that can be used with delivery systems of theinvention each include a stent within which a valve structure can beattached. The stents used with delivery systems and methods of theinvention include a wide variety of structures and features that can beused alone or in combination with other stent features. In particular,these stents provide a number of different docking and/or anchoringstructures that are conducive to percutaneous delivery thereof. Many ofthe stent structures are thus compressible to a relatively smalldiameter for percutaneous delivery to the heart of the patient, and thenare expandable either via removal of external compressive forces (e.g.,self-expanding stents), or through application of an outward radialforce (e.g., balloon expandable stents). The devices delivered by thedelivery systems described herein can be used to deliver stents, valvedstents, or other interventional devices such as ASD (atrial septaldefect) closure devices, VSD (ventricular septal defect) closuredevices, or PFO (patent foramen ovale) occluders.

Methods for insertion of the replacement heart valves of the inventioninclude delivery systems that can maintain the stent structures in theircompressed state during their insertion and allow or cause the stentstructures to expand once they are in their desired location. Inparticular, the methods of implanting a stent can include the use ofdelivery systems or a valved stent having a plurality of wires withcoiled or pigtail ends attached to features of the stent frame. Thecoiled wire ends can be straightened or uncoiled to release the stent towhich they are attached. The coiled or pigtail wire end configurationallows for positive, consistent release of the stent from the deliverysystem without the associated complications that can be caused byincomplete release and/or sticking that can occur with other deliverysystems. In addition, the release of a stent from a delivery systemhaving coiled wire ends does not require the direct application of forceto the stented valve that can dislodge the valve from the desiredimplantation location.

Delivery systems and methods of the invention can include features thatallow the stents to be retrieved for removal or relocation thereof afterthey have been deployed or partially deployed from the stent deliverysystems. The methods may include implantation of the stent structuresusing either an antegrade or retrograde approach. Further, in many ofthe delivery approaches of the invention, the stent structure isrotatable in vivo to allow the stent structure to be positioned in adesired orientation.

Delivery systems and methods of the invention provide for sequentialrelease of portions of the heart valve. That is, the delivery system hasactuation capabilities for disengaging from one or more structuralfeatures of a heart valve in a first step, then disengaging fromadditional structural features of that heart valve in one or moresequential steps. In this way, the deployment of the heart valve can beperformed relatively gradually, which can provide the clinician with theopportunity to reposition or relocate the heart valve before it iscompletely released from the delivery system.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended FIGURES, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is a perspective view of one embodiment of a delivery system ofthe invention;

FIG. 2 is a perspective view of a proximal end of the delivery systemillustrated in FIG. 1;

FIG. 3 is a perspective view of a cartridge having plural wires withcoiled ends as the wires are being attached to a stent frame;

FIG. 4 is an enlarged side view of the cartridge of FIG. 3 attached tothe crowns at one end of a stent;

FIG. 5 is a side view of the cartridge and attached stent of FIG. 4 inproximity to a portion of a delivery system to which they will beattached;

FIG. 6 is a side view of a delivery system of the invention with anattached stent;

FIG. 7 is an enlarged perspective view of the coiled or pigtail ends ofwires of a delivery system attached to a stent;

FIGS. 8-10 are side views illustrating various stages of a stent beingdeployed from a delivery system of the invention;

FIG. 11 is a side view of a portion of a delivery system having wires ofdifferent lengths with coiled or pigtail ends;

FIG. 12 is a side view of a portion of another delivery system havingwires with ends that are coiled to form different numbers of loops;

FIG. 13 is a side view of a portion of another delivery system of theinvention;

FIGS. 14-16 are sequential cross-sectional side views of a stent crownin various stages of being deployed from the pigtail end of a deliverysystem of the type illustrated in FIG. 13;

FIG. 17 is a schematic front view of another embodiment of a deliverysystem of the invention;

FIG. 18 is an enlarged front view of a portion of the delivery system ofFIG. 17, showing plural coiled wires attached to crowns of a stent;

FIG. 19 is an enlarged front view of the same portion of the deliverysystem shown in FIG. 18, further showing some of the coiled wiresdetached from the crowns;

FIG. 20 is a schematic front view of the delivery system of FIG. 17,with the stent detached from all of the coiled wires of the deliverysystem;

FIG. 21 is an enlarged front view of a portion of the delivery system ofFIG. 20;

FIG. 22 is a perspective view of one of the wires of a pigtail deliverysystem of the invention;

FIG. 23 is a side view of a stent crown positioned relative to anembodiment of a delivery system;

FIG. 24 is a side view of a stent crown positioned relative to anotherembodiment of a delivery system; and

FIG. 25 is a perspective view of a sequential wire release configurationof a stent delivery system.

DETAILED DESCRIPTION

As referred to herein, the prosthetic heart valves used in accordancewith the various devices and methods of heart valve delivery may includea wide variety of different configurations, such as a prosthetic heartvalve having tissue leaflets or a synthetic heart valve havingpolymeric, metallic, or tissue-engineered leaflets, and can bespecifically configured for replacing any heart valve. That is, whilemuch of the description herein refers to replacement of aortic valves,the prosthetic heart valves of the invention can also generally be usedfor replacement of native mitral, pulmonic, or tricuspid valves, for useas a venous valve, or to replace a failed bioprosthesis, such as in thearea of an aortic valve or mitral valve, for example.

Each of the valves used with the delivery devices and methods describedherein can include leaflets attached within an interior area of a stent;however, such leaflets are not shown in many of the illustratedembodiments for clarity purposes. In general, the stents used with thedelivery systems and methods described herein include a supportstructure comprising a number of strut or wire portions arrangedrelative to each other to provide a desired compressibility and strengthto the heart valve. However, other stent structures can also beconfigured for use with delivery systems and methods of the invention,including stents that consist of foil or metal frames or inflatablelumens that can be filled with a hardenable material or agent, such asthat proposed in U.S. Pat. No. 5,554,185 (Block), for example. Althougha number of different configurations of stents can be used, in generalterms, the stents described herein are generally tubular or cylindricalsupport structures, although the diameter and shape can vary along thelength of the stent, and leaflets can be secured to the supportstructure to provide a valved stent. The leaflets can be formed from avariety of materials, such as autologous tissue, xenograph material, orsynthetics as are known in the art. The leaflets may be provided as ahomogenous, biological valve structure, such as a porcine, bovine, orequine valve. Alternatively, the leaflets can be provided independent ofone another (e.g., bovine or equine pericardial leaflets) andsubsequently assembled to the support structure of the stent. In anotheralternative, the stent and leaflets can be fabricated at the same time,such as may be accomplished using high strength nano-manufactured NiTifilms of the type produced by Advanced Bio Prosthetic Surfaces Ltd.(ABPS) of San Antonio, Tex., for example. The support structures aregenerally configured to accommodate three leaflets; however, theprosthetic heart valves described herein can incorporate more or lessthan three leaflets.

In more general terms, the combination of a support structure with oneor more leaflets can assume a variety of other configurations thatdiffer from those shown and described, including any known prostheticheart valve design. In certain embodiments of the invention, the supportstructure with leaflets can be any known expandable prosthetic heartvalve configuration, whether balloon expandable, self-expanding, orunfurling (as described, for example, in U.S. Pat. Nos. 3,671,979;4,056,854; 4,994,077; 5,332,402; 5,370,685; 5,397,351; 5,554,185;5,855,601; and 6,168,614; U.S. Patent Application Publication No.2004/0034411; Bonhoeffer P., et al., “Percutaneous Insertion of thePulmonary Valve”, Pediatric Cardiology, 2002; 39:1664-1669; Anderson HR, et al., “Transluminal Implantation of Artificial Heart Valves”, EURHeart J., 1992; 13:704-708; Anderson, J. R., et al., “TransluminalCatheter Implantation of New Expandable Artificial Cardiac Valve”, EURHeart J., 1990, 11: (Suppl) 224 a; Hilbert S. L., “Evaluation ofExplanted Polyurethane Trileaflet Cardiac Valve Prosthesis”, J ThoracCardiovascular Surgery, 1989; 94:419-29; Block P C, “Clinical andHemodyamic Follow-Up After Percutaneous Aortic Valvuloplasty in theElderly”, The American Journal of Cardiology, Vol. 62, Oct. 1, 1998;Boudjemline, Y., “Steps Toward Percutaneous Aortic Valve Replacement”,Circulation, 2002; 105:775-558; Bonhoeffer, P., “TranscatheterImplantation of a Bovine Valve in Pulmonary Position, a Lamb Study”,Circulation, 2000:102:813-816; Boudjemline, Y., “PercutaneousImplantation of a Valve in the Descending Aorta In Lambs”, EUR Heart J,2002; 23:1045-1049; Kulkinski, D., “Future Horizons in Surgical AorticValve Replacement: Lessons Learned During the Early Stages of Developinga Transluminal Implantation Technique”, ASAIO J, 2004; 50:364-68; theteachings of which are all incorporated herein by reference).

Optional orientation and positioning of the stents of the invention maybe accomplished either by self-orientation of the stents (such as byinterference between features of the stent and a previously implantedstent or valve structure) or by manual orientation of the stent to alignits features with anatomical or previous bioprosthetic features, such ascan be accomplished using fluoroscopic visualization techniques, forexample. For example, when aligning the stents of the invention withnative anatomical structures, they should be aligned so as to not blockthe coronary arteries, and native mitral or tricuspid valves should bealigned relative to the anterior leaflet and/or thetrigones/commissures.

The support structures of the stents can be wires formed from a shapememory material such as a nickel titanium alloy (e.g., Nitinol). Withshape memory material, the support structure is self-expandable from acontracted state to an expanded state, such as by the application ofheat, energy, and the like, or by the removal of external forces (e.g.,compressive forces). This support structure can also be repeatedlycompressed and re-expanded without damaging the structure of the stent.In addition, the support structure of such an embodiment may be lasercut from a single piece of material or may be assembled from a number ofdifferent components. For these types of stent structures, one exampleof a delivery system that can be used includes a catheter with aretractable sheath that covers the stent until it is to be deployed, atwhich point the sheath can be retracted to allow the stent to expand.

The stents can alternatively be a series of wires or wire segmentsarranged so that they are capable of transitioning from a collapsedstate to an expanded state with the application or removal of externaland/or internal forces. These individual wires comprising the supportstructure can be formed of a metal or other material. Further, the wiresare arranged in such a way that the stent can be folded or compressed toa contracted state in which its internal diameter is considerablysmaller than its internal diameter when the structure is in an expandedstate. In its collapsed state, such a support structure with an attachedvalve can be mounted over a delivery device, such as a balloon catheter,for example. The support structure is configured so that it can bechanged to its expanded state when desired, such as by the expansion ofa balloon catheter or removal of external forces that are provided by asheath, for example. The delivery systems used for such a stent can beprovided with degrees of rotational and axial orientation capabilitiesin order to properly position the new stent at its desired location.

Referring now to the Figures, wherein the components are labeled withlike numerals throughout the several Figures, and initially to FIGS.1-10, one embodiment of a stent delivery system is illustrated. Thissystem can include a cartridge for initial attachment of a stent and/orstent device to the stent base device and subsequent attachment to thedelivery system, thereby providing quick and simple attachment of astent to a delivery system by an operator. In one embodiment, theattachment mechanism is a dovetail type of connection, which includes amating feature on both a cartridge and a delivery system that allows thestent to be preloaded to the cartridge and easily attached by theclinician to the delivery system. Other connection means are alsocontemplated, such as snap-fit connections, threaded connections, clips,pins, magnets, and/or the like. Alternatively, the pigtail deliverysystem may include more permanently attached components that do not usefeatures of a cartridge-based system.

One delivery system of the invention can further include a series ofwires for connecting the stented valve to the delivery system. In oneembodiment, each of the wires can be formed at its distal end into acoiled or “pigtail” configuration. The coiled end of each wire can besecured to a feature of a stent, such as a stent crown, when the wireend is coiled. Straightening the wire can then release the stent featureto which it was secured, as is described below in further detail.

One exemplary embodiment of a wire 20 having a coiled distal end 82 anda proximal end 84 is illustrated in FIG. 22. The wire can be bent atapproximately a 90 degree angle between the distal end 82 and proximalend 84, or it can be bent at an angle other than 90 degrees, or it canbe a straight wire portion with no bend or curves. As shown, the distalend 82 of the wire 20 is shaped to create approximately 1½ coils orloops; however, the wire 20 may include more or less coils or loops thanshown. The wires can be made of a wide variety of materials, such ashigh tensile strength spring wire material or NiTi, for example.Alternatively, the wire can be somewhat malleable such that it does notnecessarily return to the original coil shape once any stented valvefeatures have been released from the wire.

The size and exact configuration of the pigtail end portion of each wirecan be chosen or designed so that the forces required to retract anddeploy the stent are within a desirable range. The pigtail portion ofthe wire should be strong enough to prevent inadvertent release from thedelivery system during stent positioning, resheathing, repositioning,and/or the like. In addition, the pigtail portion of the wire should besufficiently flexible that it does not require excessive force tostraighten it during implant device deployment. In one exemplaryembodiment, the wire 20 is approximately 0.010 inches in diameter,thereby requiring approximately 7 pounds of pull force to uncoil thedistal end 82 of the wire 20. However, different materials and differentsized wires can be used for the pigtail wires that provide differentdelivery system properties.

The proximal end 84 of each of the wires 20 is fixed to a hub or baseportion that is located on a center lumen of the cartridge or deliverysystem. The wire 20 can be secured to the hub or base portion usingvarious mechanical methods and/or adhesives. In one embodiment, thecoiled or pigtail portions at the distal end 82 are initially coiledaround the wires of one end of a stent and then are fully or partiallystraightened to deploy the stented valve. The wire can be made of springmaterials or shape memory materials that may be cured or “set” via aheat treating process so that the coiled wire end can be retracted,clocked, redeployed, disengaged, or the like without the use ofadditional tools or the management of removed parts. In particular, thewires that have a pigtail portion at their distal ends are retractedrelative to one or more tubes in which they are enclosed until thepigtail portions are adjacent to one end of one of the tubes. That is,the wires are pulled relative to the tube(s), the tube(s) are pushedforward relative to the wires, or both the wires and the tubes are movedrelative to each other. The diameter of the coil circle or loop can berelatively large in size as compared to the diameter of the tube openinginto which they are being pulled so that the coils will contact andinterfere with the end of the tube when they are pulled toward it. Thewires are then pulled further back into the tube, thereby straighteningthe pigtail portions until they are released from the stent wires theyhad been encircling. In one embodiment, interference between the largerarea or volume of the pigtail portions and the inner area of the tubeforces the pigtail portions to uncoil or straighten as they are pulledinto the tube. Alternatively, the coiled diameter of the loops can berelatively small in size as compared to the diameter of the tubes intowhich they are being pulled (see FIG. 13, for example), so that thestent crown will instead contact and interfere with the end of the tubeswhen they are pulled toward it. This will inhibit the stent movement sothat additional pulling force on the wires will cause the coiled wireend to uncoil.

In particular, FIG. 1 illustrates one exemplary delivery system 10 for apigtail type of system that generally includes a proximal end 12 and adistal end 14.

FIG. 2 shows an enlarged view of the proximal end 12 of the deliverysystem 10 of FIG. 1, which includes a first knob 30 and a second knob 32for use in controlling the delivery and deployment of a stent at thegenerally distal end 14, as will be described in further detail below. Adelivery system for percutaneous stent and valve delivery can comprise arelatively long delivery system that can be maneuvered through apatient's vasculature until a desired anatomical location is reached. Inany case, the delivery system can include features that allow it todeliver a stent to a desired location in a patient's body.

A cartridge 16 is illustrated in FIG. 3 adjacent to a stent 18 to whichit will be attached. The stent 18 is then illustrated in FIG. 4 asattached to the cartridge 16 via the coiled or pigtail ends of the wires20. That is, the cartridge 16 includes a post 19 having a series ofwires 20 extending from one end and a dovetail attachment portion 22 atthe opposite end. Each of the wires 20 includes a generally straightportion that is connected to the post 19 at its proximal end 84 andfurther includes a “pigtail” or curled portion at its distal end 82.Each wire 20 is made of a shape-memory type of material (e.g., Nitinol)such that it can be straightened by applying an external force when inthe proximity of a stent to which it will be attached and returngenerally to its curled configuration when the straightening force isremoved. Alternatively, a wire can be used that is permanently deformedwhen sufficient force has been applied to it to release the stentedvalve from the delivery system.

In order to load a stent onto the wires 20 of cartridge 16, the curledend of each wire 20 can be straightened or partially straightened andplaced adjacent to one of the crowns or “V” ends of the stent. The forceon each wire 20 can then be removed or reduced so that the distal end ofthe wire coils back toward its pigtail configuration, thereby wrappingaround and capturing one crown of the stent 18, as is shown in FIG. 4.Alternatively, a malleable type of wire material can be used, whereinthe coil can be formed by wrapping the wire around the stent crownduring the stent loading process. If a different stent construction isused, the coiled wires can instead engage with some other feature ofthat type of stent. The cartridge is preferably provided with the samenumber of wires having pigtail or coiled wire ends as the number ofcrowns provided on the corresponding stent, although the cartridge canbe provided with more or less wires having coiled ends. It is alsocontemplated that a single crown of a stent may have more than onepigtail wire attached to it. After the wires 20 of the cartridge 16 areattached to the stent 18, as is illustrated in FIG. 4, the cartridge andstent combination can then be attached to the delivery system 10.

The use of a cartridge with the delivery systems of the invention canprovide advantages to the stent loading process. For example, acartridge and stent can be provided to the clinician with the stentpre-attached to the cartridge so that the clinician does not need toperform the stent attachment step prior to surgery. In addition, thecartridge concept simplifies the attachment of the valve to the deliverysystem, improves the reliability and consistency of the attachment, andeliminates the chance that the valve will mistakenly be attachedbackwards onto the delivery system.

The exemplary stent 18, one end of which is shown in the Figures, ismade of a series of wires that are compressible and expandable throughthe application and removal of external forces, and may include a seriesof Nitinol wires that are approximately 0.011-0.015 inches in diameter,for example. That is, the stent 18 may be considered to be aself-expanding stent. However, the stent to which the pigtail wireportions of the invention are attached can have a number of differentconfigurations and can be made of a wide variety of different materials.In order to be used with the delivery systems of the invention, however,the stent is preferably designed with at least one point or feature towhich a coiled wire end can be attached. That is, while an open-endedtype of stent crown is shown, other stent end configurations canalternatively be used, such as eyelets, loops, or other openings.

FIG. 5 illustrates one end of the delivery system 10 as having adovetail portion 24 that can mate or attach to a corresponding dovetailattachment portion 22 of the cartridge 16 by positioning the two piecesso that they become engaged with each other. This particular dovetailarrangement is exemplary and it is understood that a differentmechanical arrangement of cooperating elements on two portions of adelivery system can instead be used, where the stent structure isattached to one of the pieces of the delivery system, which in turn ismechanically attachable to another piece of the delivery system. It isfurther contemplated that the wires with pigtail ends are not part of acartridge-based system, but that the wires are instead attached directlyto a delivery system that does not include a cartridge.

As shown in FIGS. 6 and 7, after the cartridge 16 is attached to thedelivery system 10, the cartridge 16 and its attached stent 18 are thenretracted into a hollow tube or lumen 26 of the delivery system bymoving or pulling the cartridge 16 toward the proximal end of thedelivery device. This movement is continued until the crowns of thestent 18 are adjacent to the end of the lumen 26. It is noted that thelumen 26 may be an outer sheath of the system or that it may be an innerlumen such that another sheath or tube can be positioned on the outsideof it. Due to the compressible nature of the stent 18, continuedmovement of the cartridge 16 toward the proximal end of the deliverydevice will pull the wires 20 toward a central lumen 28 of the deliverysystem, thereby also pulling the wires of the stent 18 toward thecentral lumen 28. The cartridge 16 can then continue to be moved towardthe proximal end of the device until the stent 18 is completely enclosedwithin the lumen 26, as is illustrated in FIG. 1. One exemplaryprocedure that can be used for such a retraction of the stent 18 intothe lumen 26 is to turn the knob 32 (see FIG. 2) in a first direction(e.g., clockwise) until the knob is fully forward. The knob 30 can thenbe pulled while turning the knob 32 in a second direction that isopposite the first direction (e.g., counter clockwise) until the stentis retracted into the delivery system.

FIGS. 8-10 illustrate the deployment of the stent 18 via a deliverysystem, which would be initiated once the stent 18 is generally locatedin its desired anatomic position within a lumen (e.g. heart valve area)of the patient. In particular, FIG. 8 shows the proximal end of adelivery system as the lumen 26 is being moved away from a distal tip 29of the delivery system, thereby exposing the free end of the stent 18(i.e., the end of stent 18 that is not attached to the coiled wires 20).In this way, the compressive forces that were provided by enclosing thestent 18 within the lumen 26 are removed and the stent 18 can expandtoward its original, expanded condition. FIG. 9 illustrates the nextstep in the process, where the lumen 26 is moved even further from thedistal tip 28 of the system, thereby allowing the entire length of thestent 18 to be released from the interior portion of lumen 26 forexpansion thereof.

In order to release or deploy the stent 18 from the delivery system 10,the wires 20 are then pulled via an actuating mechanism of the deliverysystem back toward the proximal end of the device until the coiled orpigtail portions are immediately adjacent to the end of the lumen 26, asillustrated in FIG. 10. Next, the cartridge 16 with extending wires 20,along with the lumen 26 to which they are attached, are pulled furthertoward the proximal end of the device until the coiled ends of the wires20 contact and interfere with the end of the lumen 26, which therebyforces the wires 20 to uncoil or straighten at their distal ends. Oncethe wires 20 are sufficiently straightened or uncoiled, the wires 20become disengaged from the stent 18, thereby causing the stent 18 to bein its released position within the patient. One exemplary sequence ofsteps that can be used for such a final deployment of the stent 18relative to the lumen 26 with this delivery system is to turn knob 32(see FIG. 2) in a first direction (e.g., clockwise) until the stent isexposed or deployed beyond the lumen 26. Knob 30 can then be retracted,thereby fully releasing the stent 18 from the delivery system.

It is noted that in the above procedure, the stent can be retracted backinto the lumen 26 at any point in the process prior to the time that thewires 20 are disengaged from the stent 18, such as for repositioning ofthe stent if it is determined that the stent is not optimally positionedrelative to the patient's anatomy. In this case, the steps describedabove can be repeated until the desired positioning of the stent isachieved.

In a delivery system that uses the dovetail connection described aboveor another configuration that allows the stent to be connected to coiledwires of a cartridge, a cartridge can alternatively be pre-attached to avalved stent, packaged together within a gluteraldehyde solution, andprovided in this pre-assembled manner to a clinician. In this way, theclinician can simply remove the assembly at the time of the implantationprocedure and attach it to the delivery system, which can reduce theamount of time the valved stent needs to be manipulated immediatelyprior to the time of implantation.

With this system described above, full or partial blood flow through thevalve can advantageously be maintained during the period when thestented valve is being deployed into the patient but is not yet releasedfrom its delivery system. This feature can help to prevent complicationsthat may occur when blood flow is stopped or blocked during valveimplantation with some other known delivery systems. This alsoeliminates or reduces the need for additional procedural steps, such asrapid pacing, circulatory assist, and/or other procedures. In addition,it is possible for the clinician to thereby evaluate the opening andclosing of leaflets, examine for any paravalvular leakage and evaluatecoronary flow and proper positioning of the valve within the targetanatomy before final release of the stented valve.

The system and process described above can include simultaneous orgenerally simultaneous straightening of the wires so that they alluncoil or straighten at their distal ends to disengage from the stent ina single step. However, it is contemplated that the wires can bestraightened in a serial manner, where individual wires, pairs of wires,or other combinations of wires are selectively straightened in somepredetermined order to sequentially deploy portions of the stent. Thiscan be accomplished either by the structure of the delivery deviceand/or the structure of the stent and/or through the operation of thedelivery system being used.

One exemplary actuating mechanism that can be used with the deliverysystem can engage all or some of the wires to allow for sequentialrelease of the various stent crowns. This serial release of crowns canbe advantageous in that it allows for a high level of control of thediametric deflection (e.g., expansion) of the proximal end of thestented valve. Also, release of high radial force stents sequentiallycan minimize injury and trauma to the anatomy. Having control of thediametric expansion of all or a portion of the stent can minimize thepossibility for device migration, tissue injury and/or embolic eventsduring device deployment. In addition, the serial or sequential releaseof crowns can require less force for any one wire or set of wires ascompared to the amount of force that is required to release all of thewires at the same time. Additionally, regions of the stent such asfixation anchors, petals, and the like could be released in a desiredsequent to optimize the positioning and consistency of deployment.Finally, release of specific regions of the stent at different axialzones or regions of varying geometry (inflow flares, bulbous regions,and the like) and/or varying radial force can enable more accurate andstable positioning and device release.

FIG. 25 illustrates one embodiment of a portion of a sequential wirerelease configuration of a stent delivery system, which includes a firstdisk 200 and a second disk 202 spaced from disk 200 generally along thesame longitudinal axis. Disk 200 includes a surface 204 from which threewires 206 extend. Disk 202 includes a surface 208 from which three wires210 extend and three apertures 212 through which the wires 206 of disk200 can extend. The number of wires and apertures of each disk can bemore or less than three, as desired. It is further understood that morethan two disks may be provided, with one or more wires being attached toeach of the disks. All of the wires 206, 210 terminate at their distalends with a coiled portion that can include any of the coiled wireproperties discussed herein. Each of the wires in the sets of wires 206,210 can have the same length or a different length so that the coiledends are at the same or a different distance from the surface 208 ofdisk 202. This wire release configuration further includes activationmembers that are shown schematically as wires 214, 216, where wires 214extend through a center aperture 218 of disk 200 and attach to the disk202 and wires 216 are attached to the disk 200. The wires 214, 216 canbe independently activated to axially move the disks 200 and 202 withtheir attached wires 210, 206, respectively. The activation wires 214,216 are intended to be representative activation means, where otheractivation means can instead be used to provide independent axialmovement of the disks 200, 202.

In another embodiment, multiple wires can be released from a stent in asequence that includes radially releasing stent wires as individualwires, wire pairs, or groups of wires around the periphery of the stent.For example, stent wires on opposite sides of the circumference can bereleased as a pair, and then the sequence can continue in a clockwise orcounterclockwise direction until all of the wires are released from thestent. This can be performed on wires in the same axial plane. It isfurther advantageous, in accordance with the invention, to sequentiallyrelease the wires from the stent among various axial planes. This can bevaluable for stents that have varying radial force in planes. In thissituation, the delivery systems can include coiled wired ends, forexample. Finally, delivery systems of the invention can also be used torelease other specific stent features and elements other than or inaddition to stent crowns and loops, such as unfurling skirts, dockinterface elements, sealing features, barbs, hooks, and the like.

FIG. 11 illustrates one exemplary embodiment of an end portion of adelivery system that includes another embodiment of a lumen 40 fromwhich the distal ends of multiple wires 42 extend. As shown, the distalend of each of the wires 42 has the same number of coils or loops;however, the distance between each of these coils and an end 44 of thelumen 40 is different. Thus, when the wires 42 are attached to a stentand pulled toward an end 44 of the lumen 40, the shortest wire 42 willcontact the lumen 40 first. Enough interference is preferably createdbetween the wire 42 and the lumen 40 so that as this shortest wire 42 ispulled into the lumen 40, it is straightened and ultimately releasedfrom the stent feature to which it is attached. The wires 42 willcontinue to be moved further toward the end 44 of lumen 40 until thenext longest wire 42 contacts the lumen, which also will be uncoiled orstraightened to release it from the stent. This process will be repeateduntil all of the wires 42 are released from the stent and the stent isfully deployed. Although only three wires 42 are shown in this figure, adifferent number of wires can instead be provided, and preferably thenumber of wires provided matches the number of crowns on the stent thatis being delivered by the delivery system. In addition, all of the wirescan have different lengths and/or numbers of windings at their distalends, or at least one of the wires can be configured identically to atleast one other wire of that delivery system. For example, the deliverysystem can include identical pairs of wires such that each wire pairreleases from a stent simultaneously during the stent deploymentprocess.

FIG. 12 illustrates another exemplary embodiment of an end portion of adelivery system that is similar to that of FIG. 11 in that it includes alumen 50 from which the distal ends of multiple wires 52 extend. Again,the wires 52 are not all configured identically to each other. As shownin this figure, the distal ends of each of the wires 52 has a differentnumber of windings at its coiled end so that when the wires 52 areattached to a stent and pulled toward an end 54 of the lumen 50, thecoiled portions of all or most of the wires 52 will contact the end 54at generally the same time. Continued movement of the wires 52 into thelumen 50 will cause the coiled ends to simultaneously beginstraightening or uncoiling; however, the wires 52 with the least numberof windings will be completely or almost completely straightened first,thereby releasing these wires from the stent feature to which they wereattached. The movement of the wires 52 continues until the wires withthe next greater number of windings uncoil and release from the stentand all of the wires 52 are released from the stent so that the stent isfully released. As with the embodiment of FIG. 11, this embodimentprovides for a sequential rather than simultaneous release of stentfeatures (e.g., stent crowns). It is noted that more or less than threewires 52 can be used in the system and that all of the wires 52 can bedifferent from each other or that some of the wires 52 can be configuredidentically (e.g., in wire pairs that release simultaneously).

A distal end of another exemplary embodiment of a delivery system of theinvention is illustrated in FIGS. 13-16. This delivery system provides astructure for attachment of a stent or stented valve that allows forfull diametric expansion and assessment of the stent or stented valveprior to its release from the delivery system. In this way, thehemodynamic performance, stability, and effect on adjacent anatomicalstructures (e.g., coronaries, bundle branch, mitral valve interference,etc.) can be assessed and if found to be inadequate or inaccurate, thestent can be recaptured and repositioned before final release of thestent from the delivery system. Alternatively, the entire stent can beremoved from a patient before it is released from the delivery system ifany undesirable results are obtained during the process of deploying thestent.

Referring more particularly to FIG. 13, an end portion of a deliverysystem is shown, which generally includes a lumen 60 having an end 64from which the distal ends of multiple wires 62 extend. This lumen 60may be the outer sheath of the delivery system. Each of the wires 62 ispartially enclosed within a tube 66, and a coiled end of each of thewires 62 extends beyond a distal end 68 of each of the tubes 66. Eachwire 62 is longitudinally moveable or slideable relative to itsrespective tube 66. The tubes 66 are preferably sized so that when thewires 62 are pulled toward the lumen 60, the coiled ends of the wires 62will contact and interfere with the ends 68 of the tubes 66. Continuedmovement of the wires 62 will then cause the wires 62 to straightenuntil they are released from the stent. These steps are illustrated witha single tube 66 in FIGS. 14-16, which show an extending coiled wire 62that is attached to (see FIGS. 14 and 15) then detached from (see FIG.16) a crown 70 of a stent that includes multiple crowns (not shown). InFIG. 14, the wire 62 is coiled around crown 70 of a stent, and then thewire 62 is moved in a direction 72 relative to the tube 66 until thecoiled wire portion contacts an end 74 of the tube 66 (see FIG. 15).This will cause interference between the coiled portion of wire 62 andthe end 74 of the tube 66. Continued movement of the wire 62 indirection 72 will cause the coiled end of the wire 66 to unfurl. Thismovement of the wire 62 in direction 72 will be continued until the wire62 is straightened sufficiently to be released from the crown 70, asshown in FIG. 16.

The tubes 66 are preferably relatively incompressible to allowsufficient tension in the coiled portion of the wires 62 for the wiresto straighten when pulled toward the lumen. In other words, theincompressibility of the tubes under tension can simulate flexiblecolumns that resist buckling when the coiled wire ends are pulledagainst them. In an alternative embodiment of the system of FIG. 13, thewires 62 can have different lengths and/or different numbers of windingsin their coils (such as in FIGS. 11 and 12, for example), to provide forsequential release of the wires. In yet another alternative embodiment,the tubes 66 can have different lengths, thereby providing differentsizes of gaps between the end of the tubes 66 and the coiled portion ofthe wires 62.

Another alternative stent wire release embodiment is illustrated in FIG.23 with an end portion of a tube 150 in which a coiled end 152 of a wire154 is positioned. Coiled end 152 is attached to a stent crown 156 andis at least partially enclosed or contained within the tube 150. Inorder to detach the wire 154 from the stent crown 156, a retractionforce is applied to wire 154 until the stent crown 156 contacts an end158 of the tube 150, which will limit further movement of the stent.Continued application of force to wire 154 will cause the coiled end 152to unfurl, thereby releasing the coiled end 152 from the stent crown156. FIG. 24 illustrates a similar wire release embodiment to thatillustrated in FIG. 23, but with an additional tube 160 positionedwithin tube 150. To release the coiled wire end from the stent crown,the wire can be unfurled by interference between an end 162 of tube 160and the coiled wire end and/or can be unfurled by movement of the wirerelative to the tube 150, as described relative to FIG. 23. It is notedthat the wire coils in these and other embodiments of the invention caninclude a complete or partial coil with multiple windings or a partialwinding, depending on the desired release properties.

FIGS. 17-21 illustrate an exemplary delivery system 100 that can be usedto provide sequential release of wires that have their coiled endsengaged with a stent 120, where the wires all have generally the sameconfiguration (i.e., length, number of coils, and the like). Deliverysystem 100 includes a lumen 102 having an end 104 from which the distalends of multiple wires 106 extend. Each of the wires 106 is partiallyenclosed within a tube 108. A coiled end 112 of each of the wires 106extends beyond a distal end 110 of each of the tubes 108. Each wire 106is longitudinally moveable or slideable relative to its respective tube108. The tubes 108 are preferably sized so that when the wires 106 arepulled toward the lumen 102 (or when the tubes 108 are moved relative tothe wires 106), the coiled ends 112 of the wires 106 will contact thedistal ends 110 of the tubes 108. Continued movement of the wires 106relative to the tubes 108 will then cause the coiled ends 112 of thewires 106 to straighten, thereby facilitating release of the stent 120from the delivery system 100.

Delivery system 100 further includes a handle 130 from which the lumen102 extends. The handle 130 includes control aspects for deployment ofthe stent 120. In particular, handle 130 includes a proximal controlknob 132, an intermediate control knob 134, and a distal control knob136. These control knobs are provided for controlling the delivery anddeployment of the stent 120. In one exemplary embodiment of theinvention, these knobs are spring-loaded such that they need to bepressed toward the handle in order to move them along a path to a newlocation. The handle 130 can also be provided with a series of detentsthat define the specific locations where the knobs can be located. Thedelivery system 100 may also include additional knobs, levers, or thelike that can be used to control the movement of the individual wires106 or groups of wires.

In order to load a cartridge system to which a stent 120 is attachedonto the delivery system 100, the control knobs 132, 134, 136 are movedinto a position that can be referred to as the “loading position”.Specific detents or other markings can be provided on the deliverysystem to indicate the correct position for the knobs. The cartridge canthen be attached to the delivery system using a dovetail connection orsome other type of secure attachment mechanism. The proximal knob 132can then be moved to a “prepare to sheath position”, while the distalknob 136 is moved to the “sheath position”, In this way, the sheath willbe moved to a position in which the stent is protected by the sheath.The delivery system can then be inserted into the patient in its desiredposition that facilitates deployment of the stent. Moving the proximalknob 132 into the “proximal end open position” and the distal knob 136to the “load position” can then deploy the stent 120. In order todischarge the stent 120, a switch on the delivery system (not shown) orsome other control mechanism can be moved into an “open position”, thedistal knob 136 can be moved to the “discharge position”, and theproximal knob 132 can be moved to its “discharge position”. Theintermediate knob 134 can be manipulated at the same time as the otherknobs in order to facilitate the loading, sheathing, deployment, anddischarge procedures.

The delivery system 100 further comprises a dual-control procedure andmechanism to sequentially pull the wires 106 into the tubes 108 todisconnect them from the crowns of the stent 120. In this embodiment, afirst group of wires 106 can first be removed from the stent 120, andthen a second group of wires 106 can be removed from the stent 120 tothereby release the stent 120 from the delivery system 100. Thus,separate mechanisms are provided within the handle 130 to allow a firstgroup of wires 106 to be pulled into the tubes 108 by manipulating oneof the control knobs, and then to allow a second group of wires 106 tobe pulled into the tubes 108 by manipulating a different control knob.Each of the groups of wires 106 may include half of the wires, or theremay be a different percentage of wires 106 in each of the groups. Thedivision of wires into groups may further include having every otherwire be included in one group and the alternating wires are included ina second group, although the wires may be grouped in a differentpattern. It is further contemplated that additional mechanisms can beprovided so that the wires are divided into more than two groups thatare controlled by separate mechanisms for sequential wire release.

FIGS. 17 and 18 illustrate the step in which the wires 106 are eachattached at their distal end 112 to a crown of stent 120. FIG. 19illustrates the step in which some of the wires 106 have been pulledinto their respective tubes 108, thereby straightening the distal end ofthe wires and detaching them from the stent 120. However, the remainderof the wires 106 remains attached to the crowns of the stent 120. FIGS.20 and 21 illustrate the step when the remaining wires 106 have beenpulled into their respective tubes 108, thereby straightening the distalend of the wires and detaching them from the stent 120. In this way, therelease of the stent 120 from the delivery system 100 is more gradualthan when all of the wires are detached from the stent at the same time.The components of the delivery system can alternatively comprisedifferent components than shown to accomplish the serial wire releaseshown more generally in FIGS. 18, 19, and 21.

The delivery systems of the invention can be used for both apical andtransfemoral procedures, for example, and may have the ability to beable to clock the stent, as desired. The delivery systems may furtherinclude a removable outer sheath that can accommodate stents ofdifferent sizes.

The process of pulling the wires toward the lumen in many of thedescribed embodiments of the invention can be accomplished in a numberof ways, such as by rotating the device over coarse threads or pushing abutton to slide it to pull the wires toward the lumen. That is, a numberof different mechanisms can be used to accomplish this movement of thewires relative to the delivery system. Further, it is noted that whilethe coiled wire ends described herein are generally shown to be engagingwith the end crowns of a stent, the coiled wire ends can instead engagewith intermediate stent crowns or other stent features. In addition,although the coiled wire ends are illustrated herein as interfacing withstent crowns that are uniformly provided at the ends of a cylindricalstent, the coiled wire designs described can also accommodate deliveryof valved stents that have non-uniform axial or longitudinal stentcrowns of stent feature attachment geometries.

The delivery systems of the invention, having a stent attached viacoiled wire ends, can be delivered through a percutaneous opening (notshown) in the patient. The implantation location can be located byinserting a guide wire into the patient, which guide wire extends from adistal end of the delivery system. The delivery system is then advanceddistally along the guide wire until the stent is positioned relative tothe implantation location. In an alternative embodiment, the stent isdelivered to an implantation location via a minimally invasive surgicalincision (i.e., non-percutaneously). In another alternative embodiment,the stent is delivered via open heart/chest surgery. In one embodimentof the invention, the stent can include a radiopaque, echogenic, or MRIvisible material to facilitate visual confirmation of proper placementof the stent. Alternatively, other known surgical visual aids can beincorporated into the stent. The techniques described relative toplacement of the stent within the heart can be used both to monitor andcorrect the placement of the stent in a longitudinal direction relativeto the length of the anatomical structure in which it is positioned.

One or more markers on the valve, along with a corresponding imagingsystem (e.g., echo, MRI, etc.) can be used with the variousrepositionable delivery systems described herein in order to verify theproper placement of the valve prior to releasing it from the deliverysystem. A number of factors can be considered, alone or in combination,to verify that the valve is properly placed in an implantation site,where some exemplary factors are as follows: (1) lack of paravalvularleakage around the replacement valve, which can be advantageouslyexamined while blood is flowing through the valve since these deliverysystems allow for flow through and around the valve; (2) optimalrotational orientation of the replacement valve relative to the coronaryarteries; (3) the presence of coronary flow with the replacement valvein place; (4) correct longitudinal alignment of the replacement valveannulus with respect to the native patient anatomy; (5) verificationthat the position of the sinus region of the replacement valve does notinterfere with native coronary flow; (6) verification that the sealingskirt is aligned with anatomical features to minimize paravalvularleakage; (7) verification that the replacement valve does not inducearrhythmias prior to final release; and (8) verification that thereplacement valve does not interfere with function of an adjacent valve,such as the mitral valve.

The present invention has now been described with reference to severalembodiments thereof. The entire disclosure of any patent or patentapplication identified herein is hereby incorporated by reference. Theforegoing detailed description and examples have been given for clarityof understanding only. No unnecessary limitations are to be understoodtherefrom. It will be apparent to those skilled in the art that manychanges can be made in the embodiments described without departing fromthe scope of the invention. Thus, the scope of the present inventionshould not be limited to the structures described herein, but only bythe structures described by the language of the claims and theequivalents of those structures.

1. A method of deploying an implantable stented device in an anatomicallocation of a patient, comprising the steps of: providing a deliverysystem comprising first and second stent engagement structures at itsdistal end; attaching a first structural element of the stented deviceto the first stent engagement structure and attaching a secondstructural element of the stented device to the second stent engagementstructure; advancing the stented device to an implantation site; andsequentially disengaging the first structural element of the stenteddevice from the first stent engagement structure of the delivery systemand then disengaging the second structural element of the stented devicefrom the second stent engagement structure.
 2. The method of claim 1,wherein the first and second stent engagement structures each comprise awire having a distal end that is coiled for engagement with the firstand second structural elements of the stented device, respectively. 3.The method of claim 1, wherein the first and second structural elementsof the stented device comprise first and second stent crowns,respectively.
 4. The method of claim 2, wherein the coiled distal end ofa first wire includes a first number of windings and wherein the coileddistal end of a second wire includes a larger number of windings thanthe first wire, and wherein the step of sequentially disengaging thefirst and second structural elements from their respective stentengagement structures further comprises activating an actuation devicethat simultaneously axially moves the first and second wires.
 5. Themethod of claim 4, wherein the activation of the actuation device causesthe coiled distal end of the first wire to uncoil for disengagement fromthe first structural element and then causes the coiled distal end ofthe second wire to uncoil for disengagement from the second structuralelement.
 6. The method of claim 2, wherein the coiled distal end of afirst wire includes a first number of windings and wherein the coileddistal end of a second wire includes a larger number of windings, andwherein the step of sequentially disengaging the first and secondstructural elements from their respective stent engagement structuresfurther comprises activating an actuation device in multiple steps tosequentially axially move the first and second wires.
 7. The method ofclaim 2, wherein the coiled distal end of a first wire and the coileddistal end of a second wire each include the same number of coils, andwherein the step of sequentially disengaging the first and secondstructural elements from their respective stent engagement structuresfurther comprises activating an actuation device in two steps tosequentially axially move the first and second wires.
 8. The method ofclaim 2, wherein the coiled distal end of a first wire and the coileddistal end of a second wire each include the same number of coils, andwherein the step of sequentially disengaging the first and secondstructural elements from their respective stent engagement structuresfurther comprises activating a first actuation device to axially movethe first wire and then activating a second actuation device to axiallymove the second wire.
 9. The method of claim 1, further comprising thestep of attaching additional stent engagement structures of the deliverysystem to additional corresponding structural elements of the stenteddevice and then sequentially disengaging the additional stent engagementstructures from their respective structural elements after the stenteddevice is advanced to the implantation site and after the first andsecond structural elements are disengaged from their respective stentengagement structures.
 10. The method of claim 2, wherein the deliverysystem further comprises a plurality of sleeves, wherein each of thewires is at least partially positioned within one of the sleeves, andwherein the wires are axially moveable relative to the sleeves in whichthey are positioned to cause the coiled distal wire ends to contact adistal end of the sleeves and uncoil for disengagement from theirrespective structural elements.
 11. The method of claim 10, wherein atleast one of the sleeves has a different length than the rest of thesleeves of the plurality of sleeves.
 12. The method of claim 1, whereinthe stented device further comprises a prosthetic valve.
 13. The methodof claim 1, wherein the first and second stent engagement structureseach comprise a wire having a distal end that comprises a hook portionfor engagement with the first and second structural elements of thestented device, respectively.
 14. The method of claim 1, wherein thefirst and second stent engagement structures each comprise a suture thatis arranged for engagement with the first and second structural elementsof the stented device, respectively.
 15. A method of deploying animplantable stented device in an anatomical location of a patient,comprising the steps of: providing a delivery system comprising aplurality of stent engagement structures at its distal end; providing astented device comprising a plurality of structural elements; engagingeach of the structural elements of the stented device with one of thestent engagement structures; advancing the stented device to animplantation site; and sequentially disengaging the structural elementsof the stented device from their respective stent engagement structuresof the delivery system.
 16. The method of claim 15, wherein the step ofsequentially disengaging the structural elements from their respectivestent engagement structures further comprises disengaging a first set ofstructural elements and then disengaging a second set of structuralelements, wherein the first and second sets of structural elements eachcomprise at least two structural elements.
 17. The method of claim 16,wherein the step of sequentially disengaging the structural elementsfrom stent engagement structures comprises radially disengaging thefirst and second sets of structural elements from their respective stentengagement structures.
 18. The method of claim 15, wherein each of theplurality of stent engagement structures comprises a wire having adistal end that is coiled for engagement with one of the structuralelements of the stented device.
 19. The method of claim 18, wherein thedelivery system further comprises a plurality of sleeves that each atleast partially surround one of the wires, and wherein the wires areaxially moveable relative to the sleeves in which they are positioned.20. The delivery system of claim 19, wherein at least one of the sleeveshas a different length than at least one of the other sleeves.
 21. Thedelivery system of claim 18, wherein the coiled distal end of each ofthe wires can be at least temporarily deformed for engagement anddisengagement with the structural elements of the stented device.